Typical wireless communication apparatuses each include therein a tuning unit configured to match the impedance of an antenna thereof with that of a communication unit thereof. Further, a method, in which such a tuning unit includes a variable impedance device therein, and changing the impedance value of the variable impedance device in accordance with the variation of the impedance of the antenna enables matching the impedance of the antenna and that of the communication unit, is well known to those skilled in the art.
In addition, technologies, which allow a mobile wireless terminal device to include an antenna tuning unit configured to perform impedance matching for all frequencies of receiving and transmitting radio signals, an antenna matching circuit control unit configured to include a variable amount of capacitance therein and perform impedance matching control on the antenna impedance of an antenna, and a controller configured to compare the level of a reception electric field of signals inputted to the mobile wireless terminal device and the level of a reception electric field of signals received at a base station communicating with the mobile wireless terminal device, and on the basis of this comparison result, perform impedance matching control on the antenna impedance by changing the amount of capacitance included in the antenna matching circuit control unit so that the antenna impedance can be optimal for a frequency of either the reception electric field of signals inputted to the mobile wireless communication terminal or the reception electric field of signals received at the base station communicating with the mobile wireless terminal device, whichever is lower in level, are well known to those skilled in the art (refer to Japanese Laid-open Patent Publication No. 2002-118488).
Further, a system and a method, which arbitrarily increase antenna efficiency in a transmitting frequency or a receiving frequency on the basis of a fading condition, an environmental condition, a non-ideal antenna efficiency balance, a mobile station forward versus reverse link usage condition, and a system forward versus reverse link usage condition, are well known to those skilled in the art (refer to Japanese Laid-open Patent Publication No. 2008-530957).
Frequent operations of changing the impedance value of a variable impedance device included in a matching device are likely to advance degradation of the variable impedance device. Further, performing processes of controlling the impedance value of a variable impedance device included in a matching device leads to increasing of electric power consumption.